Pre-implantation factor (PIF) may be used to treat intracellular damage. Aspects of the invention are directed to a method of treating intracellular damage comprising administering PIF to a subject in need thereof. Some aspects may be directed to methods of increasing cytokine secretion in response to intracellular damage comprising administering PIF to a subject in need thereof. The intracellular damage may be a result of a disease such as Listeria monocytogenes infection, malaria, Lyme disease, cardiovascular disease, duodenal peptic ulcer, atherosclerosis, peritonitis or tuberculosis. In some aspects, a method of treating tuberculosis is disclosed, comprising administering PIF to a subject in need thereof. In some aspects, a method of treating atherosclerosis is disclosed, comprising administering PIF to a subject in need thereof. In some aspects, a method of treating peritonitis is disclosed, comprising administering PIF to a subject in need thereof.